//时间参数
`timescale 1ns/1ns

module tb_half_adder();

reg in_1;
reg in_2;

wire sum;
wire count;

initial 
    begin
        in_1 <= 1'b0;
        in_2 <= 1'b0;
    end

//调用一些系统函数，进行观察
initial
    begin
        $timeformat(-9,0,"ns",6);
        $monitor("@time %t:in_1=%b in_2=%b sum=%b count=%b", $time,in_1,in_2,sum,count);
    end

half_adder (
    .in_1 (in_1),
    .in_2 (in_2),

    .sum  (sum), 
    .count(count)
);

endmodule